The overall objective of this research is to develop a reliable and sensitive single and multiple two-dimensional membrane oxygen electrode system as a potential screening system for chemotherapeutic agents. PBI's approach to developing this dissolved-gas measurement system is to build on an existing membrane electrode design and to use a microcomputer and an in-house developed software to overcome some of the problems associated with traditional membrane electrode technology. This non-invasive technology can be used in cell culture monitoring in studies on basic cellular metabolism on factors affecting this metabolism, and in studies on cellular changes due to cytotoxic compounds, hormones, and other pharmacologically active drugs. This can also be used to examine the toxicity and safety of various chemical agents used in food. It can be applied in clinical settings in testing different drug combinations and other combinations of of chemotherapeutic regimen. In-vitro and in-vivo applications of this technology can also be extended to the biomedical area, e.g. monitoring glucose, pCO2, in blood , etc.